Revert "block: recursive merge requests"
This reverts commit 274193224cdabd687d804a26e0150bb20f2dd52c.
We have some problems related to selection of empty queues
that need to be resolved, evidence so far points to the
recursive merge logic making either being the cause or at
least the accelerator for this. So revert it for now, until
we figure this out.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/elevator.c b/block/elevator.c
index 99838f4..91e18f8 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -515,7 +515,6 @@
struct request *rq)
{
struct request *__rq;
- bool ret;
if (blk_queue_nomerges(q))
return false;
@@ -529,21 +528,14 @@
if (blk_queue_noxmerges(q))
return false;
- ret = false;
/*
* See if our hash lookup can find a potential backmerge.
*/
- while (1) {
- __rq = elv_rqhash_find(q, blk_rq_pos(rq));
- if (!__rq || !blk_attempt_req_merge(q, __rq, rq))
- break;
+ __rq = elv_rqhash_find(q, blk_rq_pos(rq));
+ if (__rq && blk_attempt_req_merge(q, __rq, rq))
+ return true;
- /* The merged request could be merged with others, try again */
- ret = true;
- rq = __rq;
- }
-
- return ret;
+ return false;
}
void elv_merged_request(struct request_queue *q, struct request *rq, int type)